Automotive exhaust system

ABSTRACT

An automobile exhaust system is provided with a muffler having a separate composite outer shell encasing the muffler to provide an auxiliary flow path for exhaust gases escaping from the muffler, the shell having longitudinal reinforcing ribs extending along its central portion serving also as fins for heat dissipation. The shell is of corrosion resistant material suited to withstand damage from road salt, and constructed to facilitate ready access to the muffler of the system.

United States Patent Wright et al.

[151 3,677,365 [451 July 18,1972

[54] AUTOMOTIVE EXHAUST SYSTEM [72] Inventors: Peter C. Wright,Etobicoke; Donald L.

Kirsch, Toronto, Ontario, both of Canada [73] Assignee: Gidou IndustriesLimited, Rexdale, 0n-

tario, Canada [22] Filed: Dec. 9, 1970 21 App1.No.: 96,429

52 us. (:1 ..'.l8l/72, 181/62 51 1111. c1. F0116 7/00 [58] FleldofSearch..181/72,62,6l,42,41,38, 181/352, 36.2; 180/64 A; 138/97, 99; 137/315[56] References Cited UNITED STATES PATENTS 3,080,940 3/1963 JObSOll..181/61 788,242 4/1905 Broga ...l8l/62 x 2,966,226 12/1960 KaliS ..18172 3,233,699 2/1966 Plummet 181/62 1,299,326 4/1919 Gray ..181/382,541,373 2/1951 McLeod ..181/62 X FOREIGN PATENTS OR APPLICATIONSPrimary Examiner-Richard B. Wilkinson Assistant Examiner-John F.Gonzales Attorney-Leon Arthurs ABSTRACT An automobile exhaust system isprovided with a muffler having a separate composite outer shell encasingthe muffler to provide an auxiliary flow path for exhaust gases escapingfrom the muffler, the shell having longitudinal reinforcing ribsextending along its central portion serving also as fins for heatdissipation. The shell is of corrosion resistant material suited towithstand damage from road salt, and constructed to facilitate readyaccess to the muffler of the system.

7 China, 5 Drawing figures Great Britain ..181/62 Patented July 18, 19722 Sheets-Sheet l INVENTOR v DIL'KIRSCH 6 P5. WR/G H T BY gem Mw ATTORNEYPafnted July 18, 1972 3,677,365

2 Sheets-Sheet 2 INVENTORl ATTORNEY AUTOMOTIVE EXHAUST SYSTEM Thisinvention is directed to an Automotive Exhaust System and, inparticular, to a system of this nature which is protected against manyof the hazards to which the conventional automobile muffler isordinarily exposed.

Within the context hereof, an automotive muffler is herein deemed toinclude the entire combination of the conventional sound chamber as wellas the inlet and outlet pipes with which said chamber is normallyequipped. One of these pipes, of course, constitutes or forms part ofthe familiar tail pipe while the other constitutes or forms part ofpiping communicating between the sound chamber and the exhaust manifoldof the engine.

ln the past, the conventional muffler was exposed to a variety ofdestructive forces which attacked it not only in its interior but on itsexterior as well. That is to say, the gases vented through the mufflerand their condensates had a corrosive effect on its interior while itsexterior was always subject to damage by flying road debris, by watersplash, by de-icing chemicals, and so forth. Moreover, it need hardly beobserved that these various hazards, all hereinafter referred to asenvironmenal hazards conduced to perforation of the muffler with theconsequent escape of exhaust gas therefrom into the body of the vehicle.In addition and apart from this most serious problem, virtually anyother damage to the muffler, tended to shorten its functional lifetime.

The invention seeks to overcome these aNd other disadvantages of theprior art in part, at least, as well as in effect by sheathing the saidmuffler in an outer shell to protect it against the internal andexternal hazards aforesaid. ln addition, the invention furthervisualizes the creation of a secondary flow path between the muffler andthe outer shell whereby gases escaping from the muffler may be conveyedto and vented at a hannless location.

The respective objects of the invention may, therefore, be brieflysummarized as the provision of:

a. An improved exhaust system;

b. An exhaust system which includes a more or less conventional mufflerfunctioning in a more or less conventional manner but protected to adegree against the-environmental hazards aforesaid, and

c. An exhaust system comprising a muffler and a protective outercovering capable of easy assembly about the muffler and of easyattachment to an automotive vehicle as herein visualized.

In particular, the invention further seeks to provide an exhaust systemwith structure establishing a main flow path through which the exhaustgases from the engine are vented to the atmosphere and a secondary orauxiliary flow path for similarly venting said gases in emergencies suchas when the said gases escape prematurely from the muffler.

ln accordance with the invention, there is provided an exhaust system asaforesaid which is comprised of two subassemblies namely, a mufflerhaving a sound chamber with manifold and tail pipes providing a primaryflow path through which exhaust gases from the exhaust manifold of theengine are vented to the atmosphere and a composite outer shell forassembly about the muffler to enclose it and protect it against theenvironmental hazards aforesaid; the outer shell being spaced from themuffler which it contains in substantially fixed co-axial relationtherewith.

Other objects of the invention, more or less broad than the foregoing,will become apparent from the following description of the elements,parts and principles constituting the invention; a preferred embodimentwhereof is illustrated by way of example only in the drawings hereuntoannexed wherein like reference devices refer to like parts of theinvention and wherein:

FIG. 1 is a general view of the total assembly in an installation,portions thereof being sectioned for ease of reference;

FlG. 2 is a part of a general view as a section at the rear supportclamp, looking forward;

FIG. 3 is a section at the front clamp, looking forward;

FlG. 4 is an exploded view of the component parts of FIG. 5, and

FIG. 5 is a general view of the fore-part of the assembly of FIG. 1,showing particulars of spacers.

ThP exhaust system visualized by the invention is comprised of two mainsub-assemblies, namely, the muffler M and an outer shell S in which itis sheathed or enclosed and by which it is protected against the manyconventional and well-known environmental hazards aforesaid.

Said muffler M is comprised of sound chamber 10, provided with amanifold pipe 12 and a tail pipe 14, which may be of any required lengthor be coupled to other piping in a wellknown manner.

The outer shell S is a composite of an intermediate housing 20 capableof accommodating sound chamber 10 both axially and radially and hasfacilities to be described for coupling to sleeves 22 and 24respectively accommodating the manifold and tail piping l2 and 14.

lt is desirable, for reasons which will appear, that the muffler M becontained in substantially fixed co-axial relation within the outershell S and in spaced relation thereto so as to create an auxiliary flowpath for exhaust gases which may escape from said muffler M when and ifthe latter is perforated.

To position these sub-assemblies in the co-axial, spaced. relationaforesaid, spacers 26 are provided, in this instance. within the sleeves22 and 24 providing for centering of the manifold and tail pipes 12 and14 therein.

The sound chamber 10 of muffler M is provided with upstanding beading 28at its ends 30-30 and, in the preferred form of the invention, suchbeading 28 is frictionally engaged within intermediate housing 20thereby effectively centering the sound chamber 10 therein with theintermediate portion thereof between the beaded ends 30-30, spacedslightly from housing 20 as shown in the drawing at 34.

Said housing 20 isexteriorly ribbed as by fins 36 for various reasonsincluding, especially, the re-inforcement and protection thereof againstdamage by stones or other road debris thrown against it in the normalcourse of highway travel.

It is a common view of those in the art, that exhaust systems of thetype visualized function best at high heat which, presumably, promotesand enhances final combustion of the exhaust gases.

The invention accordingly contemplates the provision of insulation 40particularly in the spaces 42 between the pipes 12 and 14 and thesleeves 22 and 24 in which they are respectively sheathed. It is, ofcourse, preferred that the said insulation 40 be sufficiently porous soas not to completely obstruct the emergency flow of exhaust gasesthrough said spaces 42.

ln the present embodiment of the invention, the space 34 between soundchamber 10 and its housing 20 is too narrow to accommodate insulatingmaterial. However, it'will be understood that in a situation of thisnature, a degree of thermal protection is nevertheless inherent in andafforded by the space 34 itself. Moreover, the housing 20 may also beformed of a reflective material e.g. aluminum which will furtherrestrict loss of heat from sound chamber 10.

Structurally, the sleeve 22 may be a composite of the two parts 22'22'shown by the exploded view of FIG. 4 which are capable of beingassembled into tubular relation in an obvious manner to enclose manifoldpipe 12 extending from one end of the sound chamber 10 and the oppositesleeve 24 may be likewise composed of two parts 24'24' for assemblyabout the tail pipe 14. Housing 20 may be of unitary construction asshown as well as of substantially uniform cross-section throughout itslength which should preferably exceed that of the sound chamber 10 whichit harbours thus providing a significant overlap at each end of thesound chamber 10 which acts as a socket 44 for accommodating a shoulder46 extending from sleeve 22 or 24 as the case may be.

Said sleeves 22 and 24, encasing manifold and tail pipes 12 and 14, thusinterfit telescopically with housing 20 for the sound chamber 10 ofmuffler assembly M.

Reference has been made above to the fact that the manifold and tailpipes 12 and 14 may be coupled to extensions as illustrated in thedrawing; this being the rule rather than the exception. Customan'ly saidmanifold and tail extensions 48 and 50 interconnect telescopically andfrictionally with the muffler pipes 12 and 14.

As will be understood and is shown in the drawing, the said overlaps5252 are also encased within sleeves 22 and 24.

In the preferred form of the invention each said overlap 52 is embracedbetween the rounded bight of a U-bolt 56 and a saddle 58 which ensleevesthe threaded U-bolt legs 60-60 substantially as shown in said FIG. 4 andalso in FIG. 3.

By tightening nuts 62-62 on said legs 6060, the U-bolt 56 and saddle 58are clamped about the overlap 52 deforming the component pipe and itsextension to retain these parts in engagement with each other in amanner which will be obvious from PK]. 2.

As will be further understood and is shown in FIG. 4 the sleeves 22 and24 are contoured to embrace each said U-bolt 56 and its saddle 58 whenclamped about an overlap 52 as aforesaid. Moreover, said U-bolt legs6060 are also of sufficient length to engage in mounting bracket 64secured to a frame part F of the automobile mounting the present exhaustsystem, being attached thereto by nuts 66 in an understood and obviousmanner.

lt will thus be seen that the sleeves 22 and 24 are assembled about theoverlaps 5252 whereby the pipe 12 and its sleeves 22 are frictionallysecured together at one of the muffler ends 30 and the correspondingpipe 14 and sleeve 24 likewise secured together at the other end 30.

The sound chamber housing 20 being frictionally engaged and held bysleeves 22 and 24, the outer shell S is thus assembled about mufflerassembly S; the two said assemblies being then effectively clampedtogether by the U-bolts 5656 by which the combination is, in its turn,attachable to the frame F of the automobile.

What we claim is:

LII

1. An exhaust system for an automobile having an internal combustionengine discharging hot, noxious gases comprising:

a muffler having a sound chamber with manifold and tail pipes throughwhich the exhaust gases aforesaid are vented from the exhaust manifoldof the engine to the atmosphere;

a composite outer shell for assembly about said muffler to enclose it,and

spacers positioning said composite outer shell in substantially fixedco-axial relation with the muffler providing a protective cover thereforand producing spacing between the shell and said manifold pipe and saidtail pipe creating an auxiliary flow path for gases escaping from thesaid muffler.

2. The system as claimed in claim 1 wherein said outer shell hasreinforcing ribbing on at least the portion thereof enclosing said soundchamber.

3. The system as claimed in claim' 2 wherein said ribbing consists offins.

4. The system as claimed in claims 1 including thermal insulationlocated about said muffler to retard heat loss therefrom.

5. The system as claimed in claim 1 including means for securing saidouter shell to a said automobile, said securing means also engaging saidmuffler and maintaining it in substantially the aforesaid fixed relationwith the outer shell.

6. The system as claimed in claim 1 wherein said composite outer shellcomprises a central portion, an inlet portion and an outlet portion,said inlet and said outlet portions being telescopably secured insliding relation with said central portion to provide accommodation tochanges of longitudinal dimension.

7. The system as claimed in claim 5 wherein said shell securing meanscomprises bolt and spacer means extending transversely through the wallof said shell to secure said muffler manifold and tail pipes incompressed relation with inlet and outlet pipes respectively ofsaicl shell.

1. An exhaust system for an automobile having an internal combustionengine discharging hot, noxious gases comprising: a muffler having asound chamber with manifold and tail pipes through which the exhaustgases aforesaid are vented from the exhaust manifold of the engine tothe atmosphere; a composite outer shell for assembly about said mufflerto enclose it, and spacers positioning said composite outer shell insubstantially fixed co-axial relation with the muffler providing aprotective cover therefor and producing spacing between the shell andsaid manifold pipe and said tail pipe creating an auxiliary flow pathfor Gases escaping from the said muffler.
 2. The system as claimed inclaim 1 wherein said outer shell has reinforcing ribbing on at least theportion thereof enclosing said sound chamber.
 3. The system as claimedin claim 2 wherein said ribbing consists of fins.
 4. The system asclaimed in claims 1 including thermal insulation located about saidmuffler to retard heat loss therefrom.
 5. The system as claimed in claim1 including means for securing said outer shell to a said automobile,said securing means also engaging said muffler and maintaining it insubstantially the aforesaid fixed relation with the outer shell.
 6. Thesystem as claimed in claim 1 wherein said composite outer shellcomprises a central portion, an inlet portion and an outlet portion,said inlet and said outlet portions being telescopably secured insliding relation with said central portion to provide accommodation tochanges of longitudinal dimension.
 7. The system as claimed in claim 5wherein said shell securing means comprises bolt and spacer meansextending transversely through the wall of said shell to secure saidmuffler manifold and tail pipes in compressed relation with inlet andoutlet pipes respectively of said shell.